Pain, Nausea and vomiting Flashcards
When is a nasopharagel airway contraindicated?
When there is a risk of skull base fracture
What are the main reason for intubation to be required during surgery?
When there is risk of aspiration
When paralysis is required for the surgery
When the patient has a difficult airway
What are some of the causes of difficult intubation?
Obese Short neck Poor mouth opening Receding chin TMJ disorder or fractured mandible
If aspiration is suspected then what steps should be taken?
Apply cricothyroid pressure
Intubate with an ET tube and refrain from ventilating
Empty stomach with an NG tube
When is mechanical ventilation indicated?
It is indicated when there is an operative need for paralysis (abdo surgery) or when paralysis is used as part of balanced anaesthesia e.g. when tidal volume and pressure need to be altered as nessesary
What is the role of A-beta fibres?
They are not normally involved in noxious signalling. They are resistant to local anesthetic blockade so patients can still feel touch and movement but not pain.
What is the role of A-delta fibres?
These are mechanoreceptors and nociceptors
What is the role of C fibres?
These are mechanoreceptors and nociceptors that are easily blocked by LA
What is the sensory neuronal pathway?
Primary sensory neurones with their cell bodies in the dorsal root ganglion synapse with second order neurones which travel up the lateral spinothalamic tract. These then synapse with third order neurones which pass from the thalamus to the sensory areas of the cortex
Why does rubbing the site of pain, using TENS and acupuncture help to reduce pain?
The gate keeping mechanism of pain. This means that triggering of mechanoreceptors causes increased activity in the gate keeping interneurone that stops the ascending pain signal through inhibition
What is the priciple of pre-emptive analgesia
By the use of local anesthesia +/- opioids, NSAIDs etc. can prevent noxious stimulation reaching the spinal cord. This will reduce post operative pain.
What kind of analgesia are opioids most effective for?
more effective for visceral analgesia than for somatic pain
What kinds of surgery will NSAIDs be most appropriate analgesia for?
They are good for body wall and orthopaedic operations
What are the risk factors for post operative nausea and vomiting?
History of PONV
History of motion sickness
Female
Post operative opiates
Give 4 examples of single agent anti-emetics?
5-HT3 antagonists e.g. ondansatron
Dexamethasome
Promethazine
Metoclopramide
